Post Office Day is observed in Japan every April 20, commemorating the establishment of the country's first modern postal service in 1871. This day celebrates the significant developments in Japan's postal system, which began after the Meiji Restoration when Baron Maejima Hisoka was appointed to develop a postal service. Maejima studied the General Post Office in Great Britain and implemented a similar system in Japan, linking Tokyo and Osaka with 65 post offices. Over the years, Japan's postal system evolved, leading to the creation of the Ministry of Communications and later the formation of Japan Post as a statutory corporation. Today, Japan Post Co., Ltd. operates under Japan Post Holdings, which also includes banking and insurance services. The observance of Post Office Day highlights the historical importance of postal services in Japan's communication and infrastructure development.